Module control 

Typed connection-multiplexing configuration and wire primitives.

This module deliberately contains no CLI, dispatcher, or live SSH runtime integration. It is the policy and protocol boundary those layers use.

Structs

AttachedSession

ControlData

Ordered session data or EOF indication.

ControlPathContext

Deterministic values used to expand an OpenSSH ControlPath template.

ControlPolicy

Typed view over the three string-valued fields currently stored in SshHostConfig.

ControlRequest

Correlated client-to-master request.

ControlResponse

Correlated master-to-client response.

ControlSocketGuard

RunningControlMaster

SessionOpenRequest

Session policy transferred to the authenticated control master.

Enums

AttachOutcome

ControlCommand

Commands accepted by OpenSSH-compatible -O control handling.

ControlConfigError

Invalid user-authored control configuration.

ControlDataStream

Byte stream represented by a data message.

ControlMasterMode

OpenSSH ControlMaster connection-selection policy.

ControlMessage

One framed message on a bssh control socket.

ControlOperation

Request operation understood by a bssh control master.

ControlPathError

Invalid or unrepresentable ControlPath values.

ControlPersist

Lifetime policy for an idle multiplexing master.

ControlProtocolError

Framing, serialization, version, or semantic-limit failure.

ControlResponseKind

Result variants needed by #286’s session and five control commands.

Constants

CONTROL_PROTOCOL_VERSION

Version of bssh’s length-prefixed JSON multiplexing protocol.

MAX_CONTROL_DATA_BYTES

Largest binary chunk carried in one data message.

MAX_CONTROL_FRAME_BYTES

Largest accepted serialized control message.

Functions

attach_session

bind_control_socket

Bind with a private temporary pathname, chmod it before publication, and hard-link it into place. No client can reach the socket while its mode is broader than 0600.

connect_control_socket

expand_control_path

Expand the #286 ControlPath token subset and validate the resulting Unix socket address before any connection or bind attempt.

prepare_attached_session

Complete the hello and OpenSession exchange without starting local I/O. Callers implementing -f may safely detach after this returns because the master has authenticated the control peer and accepted the session.

read_control_message

Read, decode, and validate one bounded big-endian-length-prefixed JSON message without allocating an attacker-declared oversized frame.

remove_stale_control_socket

Remove a refused socket only when it is still the exact same socket owned by this uid. Regular files, symlinks, replacement sockets, and foreign sockets are never removed.

send_control_command

start_control_master

start_control_master_with_bootstrap_session

Start a master and optionally let its own initial foreground passenger attach without an ask prompt. Subsequent shared sessions still honor require_confirmation.

unix_socket_path_capacity

Number of bytes in sockaddr_un.sun_path, including its terminating NUL. Non-Unix targets return None and remain compile-safe without claiming Unix-domain socket support.

validate_control_socket_path

Validate an already-expanded control socket path.

verify_same_user

write_control_message

Serialize and write one bounded big-endian-length-prefixed JSON message.